Making a battle system that include a 2D map

Mgccl

This is something hard. I don't know if I should even do it with PHP

I try to use PHP design a battle system like Final Fantasy Tatic and other games like it. a 2D map, a person can do actions, and action result changes in position and changes some people's stat.

I try to use PHP to do this, and I searched the internet and I found...
THERE is not much about 2D PHP programming, I can't even find concepts of using PHP to make 2D maps...

and what I want even more is
There is not much about using PHP make AI, and I need some AI to do responces.

so, here is everything I got... a map system, which is a 2D array

$map[$x][$y]

and the array will either be NULL or contain a object(player... wall or something)
and when a character move, the object will move and the current $map[$x][$y] will set to be null and transfer the object to another array....

looks inefficient... but I don't think there is anything better to do...

Now, some of my quesion is, if I want to know what position an object is, I have to loop though each one of the array... is there more efficient way to do it? because if the $x and $y are EXTREMELY large and there are a LOT objects... this could be pretty slow...

NogDog

I think I'd do this by storing the xy coordinate for each object with that object. This could then be saved in session variables. Then you'd have a image server script to display the map, placing each object onto the base map by using a separate image for each such object. (This all assumes access to the GD library in PHP.)

I played around with this a bit tonight, and came up with this little demo page: [deleted link: it works fine on my PC but not on my web site...I'm still trying to debug and figure out why. 🙁 ]. All the source code is on that page, but the main thing of interest is the map.php file that is the source for the map image on the index page:

<?php
session_start();
header("Content-Type: image/gif");
header("Cache-Control: no-cache");
$map = imagecreatefromgif("map.gif");
$knight = imagecreatefromgif("knight.gif");
// place "knight" object on the map based on session data:
imagecopy($map, $knight, $_SESSION['knight']['x'], $_SESSION['knight']['y'],
          0, 0, 45, 50);
imagedestroy($knight);
imagegif($map);
imagedestroy($map);
?>

Hope that gives you some food for thought.

NogDog

OK, I got my demo to work on my web host: http://www.charles-reace.com/test/map/index.php

Mgccl

Great, this is useful. I just have an array of objects, and an array of object position. This could be pretty fast. Thx. Anyway, I’m going to use Tables(or DIVs when there are people doing Ajax…) instead of use GD generate picture because that will be pretty slow and takes the load of the server. But, now I know exactly how the battle system will be formed. Maybe I should even store the all the battle objects in Session too so can be access any time. The AI part is a pain. I have to find more about it. The basic AI is to move toward the nearest Object.